The Siemens SITRANS TH320 (Model 7NG031) is a high-performance, industrial-grade temperature transmitter designed to provide reliable and high-precision process temperature measurement in various demanding industrial environments. It supports connection to multiple temperature sensors (e.g., RTD, thermocouples), features a robust housing, excellent noise immunity, and easy configuration. It is widely used in factory automation, process industries, and energy sectors.
Catalog sheet SITRANS TH320
SIEMENS SITRANS TH320 7NG031 Temperature transmitters
SITRANS TH320 and TH420 combine perfect measurement and intelligence at any temperature and condition. Real reliability is guaranteed, for example, by the dual sensor input of the TH420 incl. 4-wire sensor connection and hot backup function. In case of a sensor failure, the transmitter automatically switches to the second sensor, and the valuescontinue to be recorded seamlessly and without loss.
Overview
- 2‑wire head transmitter with and without HART communications interface
- Mounting in the connection head of the temperature sensor
- Universal input for virtually any type of temperature sensor
- Can be configured via PC, HART 7 or optional local operation
Benefits
- Compact design
- Flexible mounting and center hole allow you to select your preferred mounting type
- Galvanic isolation
- Test terminals for ammeter
- Diagnostics LED (green/red)
- Input monitoring wire break and short-circuit
- Self-monitoring
- Configuration status stored in EEPROM
- SIL2/3 (with order note C20)
- Expanded diagnostic functions, such as slave pointer, operating hours counter, etc.
- Special characteristic
- Electromagnetic compatibility according to EN 61326 and NE21
Application
SITRANS TH320 transmitters can be used in all sectors. Its compact size means that it can be installed in connection heads of type B or larger. The following sensors/signal sources can be connected over their universal input module:
- Resistance thermometer (2-wire, 3-wire, 4-wire connection)
- Thermocouples
- Linear resistance, potentiometer and DC voltage sources
With HART communications interface:
- The output signal is a load-independent direct current from 4 to 20 mA in accordance with the input characteristic, superimposed by the digital HART signal.
Transmitters of the "intrinsically safe or Zone 2 increased safety" type of protection can be installed in hazardous areas. The device meets the requirements of the EU Directive 2014/34/EU (ATEX), the FM and CSA regulations as well as other national approvals.
Function
Without HART communications interface
For the SITRANS TH320 without HART functionality, parameters are assigned with the PC. A special modem and the software tool SIPROM T are available for this purpose.
With HART communications interface:
The SITRANS TH320 is configured via HART. The configuration can be carried out using a handheld communicator or, more conveniently, with a HART modem and the SIMATIC PDM parameterization software. The configuration data is then permanently stored in the non-volatile memory (EEPROM).
After correct connection of input and supply voltage, the transmitter outputs a temperature-linear output signal and the diagnostics LED is green. In case of external errors, e.g. sensor short circuit or interruption, the LED flashes red; an internal device error is indicated by a permanent red light.
An ammeter can be connected at any time for checking and plausibility via the test terminals. The output current can be read without any interruption, or even without opening the current loop.
